A high-speed printer is provided for printing sheets or a continuous web which is then cut to sheets.
The device comprises at least one pair of conveyor belts which are diverging relative to a main transport direction such that they can move sheets laterally in different directions relative to said main transport direction.
A gripping and contact maintaining appliance is provided such that the conveyor belts can grip or engage sheets and hold them in contact with said conveyor belts for transport thereby.
Devices for lateral movement of sheets or piles of sheets during transport thereof to a stacking device, are previously known from U.S. Pat. No. 5,540,370. At these prior art devices, conveyor belts are used for lateral movement of the sheets relative to each other. For shifting the sheets between different conveyor belts and keep the sheets in contact therewith, balls affected by magnetic forces are used. Such devices however, are not suitable when it comes to transport webs of sheets or individual sheets at high speeds, e.g. 2 m/s, through high-speed printers, e.g. laser printers, for printing webs of sheets or individual sheets.
In DE 198 19 736 devices with conveyor belts are described, utilizing a vacuum for gripping and transporting sheets. Said transport belts are adapted to move together sheets from two stacks to a single stack and not to provide different piles of sheets.
In U.S. Pat. No. 4,572,497 there are described devices with conveyor belts which utilize a vacuum for gripping and transporting sheets. The conveyor belts are adapted for lateral movement of the sheets and not to provide different piles of sheets.
U.S. Pat. No. 5,133,543 relates to devices at which sheets are transported by conveyor belts and held in contact therewith by means of a vacuum. These devices are not adapted for lateral movement of sheets relative to each other, but have diverging conveyor belts for stretching the sheets. The devices are not suitable for use in connection with high-speed printers requiring high feed speeds on the webs of sheets or the individual sheets.